A curable silicone composition to be cured by a hydrosilylation reaction generally has low adhesion. Therefore, when adhesion is required, the curable silicone composition should contain an adhesion promoter. For example, Patent Document 1 discloses a curable silicone composition contains an adhesion promoter which is a cyclic siloxane or linear siloxane having an alkenyl group, and an alkoxy group or a glycidoxypropyl group that are bonded to silicon atoms.
However, such a curable silicone composition has problems in which initial adhesion and adhesion durability are insufficient with respect to a metal or an organic resin, particularly, a thermoplastic resin to be bonded to a highly polar group, under contact during curing.